Definetly not too late..

Your options depend on which branch (Air Force or Navy) you want to fly in, but because you mentioned the Air Force, I'll explain those..

You could either enroll in the Air Force ROTC at a participating college, or you could join the Air National Guard, then go to college, and try to get a pilot slot after you graduate.  The big difference between the Air Force and the Air National Guard is that the ANG is part-time, so you fly one weekend per month and there's a two week summer camp; in the Air Force you fly full time.  Your decision between the two basically lies in if you want to fly full time or part time, and if you want to go to a colleges with the AFROTC programs, or any college (you can go to any college if you're in the ANG).

You can find more info on the AFRTOC here: http://www.afrotc.com/
More info on the ANG here: http://www.goang.com/

Let me know if there's anything else you'd like to know..